Mayer M, Doenicke A, Hofmann A, Angster R, Peter K
Institut für Anaesthesiologie der LMU München, Innenstadtkliniken.
Anaesthesist. 1991 Dec;40(12):668-71.
ORG 9426 is a new non-depolarizing steroidal muscle relaxant with a short onset time and intermediate duration of action. Its ED90 ist estimated to be between 0.25 and 0.36 mg/kg. The present study investigated the onset time, duration of action and time to spontaneous recovery after 0.3 and 0.9 mg/kg ORG 9426, respectively (i.e. about single or triple ED90). METHODS. Following the consent of the ethics committee and informed patient consent, two groups of 18 patients (ASA I or II) were formed, each scheduled for general or ORL surgery. After premedication with lormetazepam, anesthesia was induced with midazolam (0.07 mg/kg) and etomidate (0.3 mg/kg) and maintained with N2O/O2 at a 65:35 ratio, enflurane (0.8-1.5%) and supplements of fentanyl as needed. The ulnar nerve was stimulated with supramaximal 2 Hz Train-of-four (TOF) every 20 s. Neuromuscular twitch response was registered with EMG. Muscle relaxation was achieved by administration of ORG 9426 0.3 (group 1) and 0.9 mg/kg (group 2), respectively. The following parameters were measured: onset time (time interval from injection to maximal or total block), T125/75 (time for T1 to reach 25% or 75% of control), TOF70 (time for TOF ratio to reach 70% of control), heart rate and blood pressure. RESULTS. (mean +/- SD). At a dosage of 0.3 mg/kg, the onset time was 3.1 +/- 0.8 min and the maximum blockade was 87 +/- 9%. A dosage of 0.9 mg/kg led to complete paralysis (100%) in all patients within 1.2 +/- 0.3 min. The time for recovery of T1 to 25 and 75% of baseline was 18 +/- 7 and 26 +/- 8 min in group 1, in group 2 46 +/- 11 and 53 +/- 17 min, respectively. TOF70 (i.e., time to adequate spontaneous recovery of neuromuscular function) was achieved after 30 +/- 10 and 63 +/- 14 min, respectively. CONCLUSIONS. At a dosage of 0.3 mg/kg, ORG 9426 has an onset time of about 3 min and a duration of activity of nearly half an hour. Its neuromuscular effects are similar to a single ED90 dose of vecuronium. In contrast to a previous study, we observed a much shorter onset time of 70 s following the administration of 0.9 mg/kg. The clinical duration of action and spontaneous recovery of neuromuscular function, however, were significantly prolonged to more than 1 h. The hemodynamic parameters showed only slight alterations.
ORG 9426是一种新型非去极化甾体类肌肉松弛剂，起效时间短，作用持续时间中等。其ED90估计在0.25至0.36毫克/千克之间。本研究分别调查了0.3毫克/千克和0.9毫克/千克ORG 9426后的起效时间、作用持续时间和自主恢复时间（即约单倍或三倍ED90）。方法：经伦理委员会批准并获得患者知情同意后，组建了两组各18例患者（ASA I或II级），均计划进行普外科或耳鼻喉科手术。用氯美扎酮进行术前用药后，用咪达唑仑（0.07毫克/千克）和依托咪酯（0.3毫克/千克）诱导麻醉，并用65:35比例的N2O/O2、恩氟烷（0.8 - 1.5%）及按需补充的芬太尼维持麻醉。每隔20秒用超强2赫兹四个成串刺激（TOF）刺激尺神经。用肌电图记录神经肌肉抽搐反应。分别给予ORG 9426 0.3毫克/千克（第1组）和0.9毫克/千克（第2组）以实现肌肉松弛。测量以下参数：起效时间（从注射到最大或完全阻滞的时间间隔）、T125/75（T1达到对照值25%或75%的时间）、TOF70（TOF比值达到对照值70%的时间）、心率和血压。结果（均值±标准差）。剂量为0.3毫克/千克时，起效时间为3.1±0.8分钟，最大阻滞为87±9%。剂量为0.9毫克/千克时，所有患者在1.2±0.3分钟内均出现完全麻痹（100%）。第1组T1恢复到基线值25%和75%的时间分别为18±7分钟和26±8分钟，第2组分别为46±11分钟和53±17分钟。TOF70（即神经肌肉功能充分自主恢复的时间）分别在30±10分钟和63±14分钟后达到。结论：剂量为0.3毫克/千克时，ORG 9426起效时间约为3分钟，活性持续时间近半小时。其神经肌肉效应与单倍ED90剂量的维库溴铵相似。与之前的研究不同，我们观察到给予0.9毫克/千克后起效时间短得多，为70秒。然而，临床作用持续时间和神经肌肉功能的自主恢复明显延长至1小时以上。血流动力学参数仅有轻微改变。
